Conventionally, there has been known a technique of detecting a phase current value of each phase with high precision in order to control a switching element of a bridge circuit that drives a polyphase electric motor to rotate, by using PWM control. For example, JP 2010-220414 A discloses a motor control device capable of ensuring highly accurate current detection. In a case where an on time of one of the low potential-side switching elements corresponding to each phase in a driving circuit becomes shorter than a current-value detection time, the motor control device estimates a phase current value of a current undetectable phase corresponding to the one of the switching elements. The motor control device estimates the phase current value of the current undetectable phase according to current values of two phases other than the current undetectable phase. Upon current detection according to the above-described estimation, the motor control device holds the switching state of the switching arm corresponding to the current undetectable phase during current detection with respect to the two phases other than the current undetectable phase which are bases for the estimation. In other words, the motor control device causes a high potential-side switching element to be turned on and the low potential-side switching element to be turned off, and thus outputs a motor control signal that prevents mixing of noise caused by switching of the switching element. Therefore, the motor control device can ensure highly accurate current detection even though an output voltage limit set for securing detection time of the phase current value in all the phases is eliminated.